Self-opening die for pipe-threading machines



Dec. 20, 1927. 1,653,258

F. M. DAVIS SELF OPENING DIE FOR PIPE THREADING MACHINES.

Filed Nov. 5. 1924' 4 Sheets-Sheet 1 WITN Z1 0%; INZENT R. fi

A TTORNEY.

ne zo, 1927.

Y I 1,653,258 F. M. DAVIS SELF OPENING DIE FOR PIPE THREADING MACHINES Filed Nov, 5. 1924 4 Sheets-Sheet 2 I2? I 4 73 [72.9 .5; 3/

INVENTOR. WIT NESSES A TTORNE Y.

Dec. 20, 1927.

F. M. DAVIS SELF OPENING? DIE FOR PIPE THREADING MACHINES Filed Nov. 3. 1924 4 Sheets-Sheet 3 INVENTOR.

h Va 1 1 I ATTORNEY.

WITNESSES Dec. 20, 1927. 1,653,258

F. M. DAVIS SELF OPENING DIE FOR PIPE THREADING MACHINES Filed Nov. 3. 1924 4 Sheets-Sheet 4 WITNESSES ATTORNEY.

Patented Dec. 20, 1927.

UNITED STA TES. PATENT OFFICE.

FRANK M. DAVIS, or MILWAUKEE, "Wisconsin.

Application filed November 3, 1924. Serial 110.747,!28.

The invention relates to thread cutting dies, more particularly for use on pipethreading machines.

An object of theinvention is to provide .a thread-cutting die for pipe-threading machines and the like, which will open upon the completion of a predetermined length of thread on the work-piece to permitthe worlepiece to be withdrawn, and which Will permit the cutting of different thread diameters.

Another object of the invention is to provide-a threadcutting die of this character in which the chips cut from the work-piece are readily and continuously removed to prevent clogging j-which would render the device temporarily inoperative and unsuitable for use inquantity production machinery. I

A further object of the invention isto perfect details of construction in a device of this character by which it may be readily assembled and dismantled, the parts being of rugged construction to insure reliable operation. a a v The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof. s

In the accompanying drawings:

Fig. l is a side elevation of a device embodying the inventionmounted on an arbor Fig. 2 is a front end view of the device;

Fig. 3 is a rear .end view of the device;

Fig.4 is a longitudinal section taken at the line l4; of Fig. 2,. interior parts being shown in elevation; s

Fig. 5 is a longitudinal section taken at the line. 55 of Fig. 2;.

Fig. 6 is a longitudinal section taken at the line 6 6, of Fig. 2;,

"Fig. 7 is a transverse section taken on line 7--7 of Fig. 5';

Fig. 8 is a front end view of the device with an end plate removed, parts being broken away and parts being shown in section;

Fig. 9 is a transverse section taken on the line 9 9 of 2, interior parts being shown in elevation;

'Fig. 10 -is a sectional detail view of amodified interior parts assembly; and

Fig. 11 is an end view thereof.

In these drawings 15 designates a rotatable. die body of general cylindrical formhaving one end interiorly threaded at 16 to be screwed onto an arbor 17 of a screw-cutting machine. The end of the die body adjacent the arbor is provided with an annular shoulder 18 and the forward end has secured to it a circular plate l9-by-sorews 20, the plate forming a shoulder at thisend of the die body. Theforward end of the die body is provided with radially extending slots 21 to receive thread-cutting chasers 22 slidably mounted .therein, these being formed to out pipe threads in the present instance,

and the forward edges of the slots being defined by the front plate 19. to prevent otherthan radial movement of the chasers in their slots.

A sleevemember23 is slidably mounted on the die body between the terminal shoulders and 'is splined thereto against rotation by longitudinally extending :key' members 24 disposed in registering grooves .25 and 26 at diametrically opposite portions of the die body and sleeve member, respectively. The forward portion of the sleeve-member has a tapered :bore 27 to the walls of which arefisecured by screws 28 spaced segmental members '29 which form guide slots 30 between them to receive the outer ends of the .chaseis 22, the outer edges 31 of which are inclined to lie adjacent the inclined edge of the slots formed by the tapered bore 27. The segmental members 29. are held in alignment by the-engagement of circumferential ribs 32 with ,an annular groove ,33 in the tapered bore. and the inner walls of the segmental members; form cylindrical surfaces Figs. 5 and 6. Ribs 34 are rmed in one edge of each segmental member to project into the guide slots .30, where they enter grooves 35 inthe chassis, as seen in Figs. 8 and 9, to form a cam connectioneffecting a radial movement :of the chasers upon a longitudinal movement of the sleevemember, as hereinafter set forth; i

The die body is provided with a central bore 3 6 in which a two-part tripping sleeve 37 is slidably mounted, the .rear part 38 of the sleeve having a threaded connection 39 with the front part 40 to afford an adjust, ment in length and the front part having spaced inwardly extending inclined projece tions 41 adapted to engage the ,end of the pipe 42 being threaded. I 1

A pair of trip levers 43 are disposed in apertures 44 connectingthe central bore 36 and the diametrically opposite grooves 25 engageable with the die body, as seen in in the die body. These levers are in the form of bell cranks and are pivotally mounted by integral trunnions disposed in slots 16 cut into the die body transversely of and projecting below the grooves 25. The forwardly projecting .leg 17 .ofeach lever is adapted to engage a shoulder 4:8 forming the end of a longitudinallyextending groove L9 in the key member 24,,into which the leg is urged by a coil spring mounted in a recess 51 in the die body, and the inwardly extending leg 52 of each lever is adapted to engage the bottom of a slot 53 in the rear part of the tripping sleeve, the sleeve being limited in its forward movement by its abut-- ment with the edges of the inwardly extending chasers 22.

For reaming the inner edge of the end of the pipe 12 to remove burrs therefrom and.

form a chamfer thereon, a blade-holder 5a is slidably mounted within the sleeve 37 and is urged forwardly by a spring 55' disposed within the bore 36 and abutting at its rear end against a circular plate 56 closing the end of the bore. At its forward end the blade-holder is provided with radially extending slots 57 to receive a number of reaming blades 58, three being used in the present instance, held therein by screws 59, and the sleeve being provided with openings 60 to afford access to the screws. The blades are provided with inclined cutting edges 61 for producing a chamfer and have radially extending projections 62 passing through slots 63 in the tripping sleeve and slidably mounted in grooves 64 in the die body so that the blades will rotate with the die body.

In the modified form of reaming device shown in Figs. 10 and 11, a single'reaming blade 58 is provided which is rivetedt-o the blade-holder 54: in a transverse slot 57. The blade is )rovided with opposite inclined cutting e ges 61 and has radially extending projections 62 adapted to be slidably mounted in the grooves of the die body to establish a driving connection. The

tripping sleeve 37 is of two-part construction as above and has a conical forward end :1 for engagement with the pipe. The blade is disposed in a diametrically extending slot 63' in the tripping sleeveto permit relative movement between these parts. In each instance the two-part tripping sleeve is prevented from losing its longitudinal adjustment at the threaded connection by the trip levers and the blades retaining the rear and front parts, respectively, against rotation.

The sleevemember 23'is slidably mounted on the die body 15 for controlling the position of the chasers 22, as above described, and is under spring pressure urging it rearwardly. For this purpose longitudinally extending channels 65. are provided at the inner ends 67 of radially extending pins 68 secured in bores 69 in the sleeve member and PlOllGCtlngiIltO the grooves. For holdmg thepins 1n the sleeve member wlth their inner ends projecting properly into the grooves 65 the pins are'providedwith transversely extending slots 7 Oat their outer ends to receive a springloop 71 extending around the sleeve member in an annular groove 72. Each key member 2a is adjustably secured to the sleeve member by an adjusting member 73 rotatably mounted in a radially eX- tending bore 7 1 in the sleeve member and having an eccentrically disposed circular projection 7 5 which enters a transverse groove 7 6 in the keymember. The outer endot the adjusting member is provided with a transverse slot 77 for receiving a screw driver or other tool, and suitable calibrations are placed at the periphery of the adjusting member for registry with a mark on the sleeve member to guide the operator in making an adjustment effecting variations in the cutting diameters of the chasers, by changing the normal forward position of the sleeve member. Each adjusting member is locked in position by a cone-pointscrew 7 8 threaded into the sleeve'member at right angles to the adjusting member in a plane normal to the axis of the sleeve member and entering "an annular groove 79 in the adj usting member.

When the sleeve member is urged forward against the action of the springs 66 to position the chasers for cutting the desired diameter of thread, the spring-urged trip levers 43 then engage the shoulders t8 in the key members 2 1 locked to the sleeve member 23 so that the latter is retained in its forward position. The rearward position of the sleeve member is determined by its abutment with an annular stop ring 80 engaging the shoulder of the die body and formed of two parts pivotally connected together at 81 to permit its ready removal after releasing a spring loop 82, which is disposed in an annular groove 88 in the two-part ring for holding it in place around the die body.

In order to prevent clogging of the die with chips, which would render the device inoperative and unsuitable for use in rapid work, provision is made for afiording an outlet for the chips at various places on the device as they are flushed by the lubricant. The central opening 36 for receiving the end of the pipe at the forward end of the device merges with an outwardly flaring conical opening 84 which is provided with flutes 85 out of which the chips descend. Inclined bores 86 extend in the die body beled l r Av i being tween central bore -36-just back of the,

then continues to movewforward at a rate determined by the pitch of the thread being formed, the sleeve member taking the radial thrust of the chasers, which are held rigidly in place, and simultaneously the reaming blades 58 yieldingly engage the inner edge of the end of the pipe to clear it of burrs and form a chamfer thereon. 1 When the pipe engages the forward conical end of the tripping sleeve 37 the latter is pushed backwardly to swing the trip levers 43 out of engagement with the shoulders 48 of the key members 24, the sleeve :member 23 then released and pushed rearwardly against the stop ring '80 by the springs (36. This movement of the sleeve brings the ehasers clear of the pipe by the camaction of theribs 34 inthe grooves 35 of the chasers, so that the die may be withdrawn from the pipe to permit the latter to be removed from the machine. placed in condition to thread the succeeding pipe by moving the sleeve member forwardly in position to have the key members 24 again engaged by-tlie-spring-urged trip levers 4L3. This movement of the sleeve member may be accomplished by a resetting member 88 adapted to be moved forwardly against it at the proper moment in the cycle 0 operation, or the die may :be moved backwardly a sufficient distance to have the sleeve member engage a stationary abutment for this purpose. It is obvious that the die may be held stationary while the work rotates.

The cliasers may be readily removed for sharpening or replaced by others for cutting different diameters after removing the stop ring 80, which permits the sleeve member to be moved back suiliciently to expose the outer edge of the chase-rs. The removal of the chasers permits the reamer and tripping sleeve assembly to be withdrawn vfrom the bore 36 for attention to the blades when necessary, and whenbthe front plate 19 is removed, the sleeve member 23 can be withdrawn, which exposes the trip levers 43, key member 24:,and1springs 50 and 66 for ready removal, The construction ofthe device likewise affords a rapid assembly and the parts are ot'rugged character for durability and strength, which enables the device to operate long periods ottime without attention. c i

The die is by Letters Patent-is:

1. In a self-opening die for pipe-thread ing machines, the combination of a die body, chasers slidablymounted in said die body, a longitudinally shiftable sleeve member.

' slidably mounted on said die body .against relative rotation and having a conical bore, at one end, an annular series of spaced wedge-shaped segmental members fixedly secured to said sleeve cmember within and abutting the conical bore and forming chaser-receiving cam slots between them for controlling the movement of said chasers in both directions, tongue-and-groove means for aligning said segmental members with in said conical bore, spring means'acting on said sleeve member for eifectingamovement of said member to chaser-inoperative position, and tripping means retaining'said sleeve -member in. chaser-operative position and controlling the movement of said sleeve member, whereby said chasers are moved to inoperative position topermit the release.

of the work atter cutting thereon a predetermined'length of three ,c

2. In a self-opening diecfor pipe-thread ing machines, the combination of a die body, chasers slidably mounted in said die body, a longitudinally shiftable sleeve :member slidably mounted'on said die body and operatively connected to said Chasers for controlling their movement in both directions, spring means acting :on said sleeve member for effecting a rearward movement of said member to chaser-inoperative position, a removable stop member on] said die body limitingmthe rearward movement of said sleeve member, and tripping means retaining said sleeve member in-chaser-operative position and. controlling the movement of said sleeve member, whereby said chasers are moved to inoperative position to permit the release of the work after cutting thereon a predetermined length of thread, and the removal of said stop member permitting an extended movement of said sleeve member to a chaser-inoperative position permit ting the radial removal of said chasers from the die body. I I I 3. In a self-opening die for pipe-threading machines, the combination of a die body,- chasers slidably mounted in said die body, a longitudinally shiftable sleeve member slidabl'y; mounted on-said die body and 0peratively connected to said ehasers for controlling their movement in bothdirections,

hat I claim as new and desire to'secure said die body and sleeve member having &

a longitudinally shittable sleeve member slidably mounted on said die body and 0p eratively connected to said chasers for controlling their movement, said die body and sleeve member having registering longitudinally extending grooves, key members slida bly mounted in said registering grooves and having transversely extending slots in their outer faces, adjusting members rotatably mounted in said sleeve member and having inwardly extending eccentric portions disposed in said transverse slots tor varying the relative positions of said key members and sleeve member, means for locking said adjusting member in position, spring-urged trigger levers pivotally mounted in said die body and engageable with said key members for retaining said sleeve member in chaser operative position, spring means acting on said sleeve member for ei'l'ectmg a movement of said member to chaser-inoperative position, a tripping member movably disposed within the die body and engageable with the work for swinging said trigger levers after a redetermined length of thread has been cut on the work whereby said sleeve member is moved to chaser-inoperative position permit the release of the work.

5. In a self-opening die for pipe-thread ing machines, the combination oi a die body, chasers slidably mounted in said die body, a longitudinally shittable sleeve member mounted on said die body and operatively connected to said chasers for controlling their movement in both directions, spring means acting on said sleeve member for effecting a movement of said member to chaser-inoperative position, tripping means for controlling the movement of said sleeve member including a tubular member slidably mounted within the die body and having inturned parts adapted to engage the end of a pipe, a spring-urged blade-holder slidably mounted within said tubular member, cutting blades secured to said blade-holder for reaming the edge of the pipe by their yieldable engagement therewith and having radially-projecting parts passing through said tubular member and engaging said die body against relative rotation, the movement of said tubular member by the Work controlling the move ment of said sleeve member to chaser-11mperative position to permit the release of the pipe after it has received a predetermined length of thread;

6. In a self-opening die pipe-thread a central bore extending inwardly from said conical bore, a shift-able sleeve-member mounted on said die body and operatively connected to said chasers for controlling their movement, spring means acting on said sleeve member for ettei-ting a movement of said members to chaser-inoperative position, tripping means for controlling the movement of said sleeve member including a part slidably mounted in the central bore of the die bod adjacent the inner ends of the chasers {111C engageable with the work for opening the chasers to permit the release of the work, and conduits connecting the central bore adjacent the chasers with the periphery of the die body, said conduits and said fluted conical central opening aitording an outlet for the chips to prevent clogging of the die.

7. In a self-opening die for pipe-threading machines, the combination of a die body having a central opening, chasers slidably mounted in said die body, a longitudinally shit-table sleeve member slidably mounted on said die body and operatively connected to said chasers for controlling their movement, in both directions, said die body and sleeve member having registering longitudinally extending grooves, key members slidablydisposed in said grooves and secured to said sleeve member in longitudinally adjust-able relation, spring means acting on said sleeve member for etlecting a movement of said member to chaser-inoperative position, spring-urged trigger levers pivotally mounted in said die body by trunnions disposed in transversely extending slots in the periphery of said die body, said trigger levers having their outer portions engageable with said key members for retaining said sleeve member in chaser-operative position, spring means acting on said sleeve member for eii'ecting a movement of said member to chaser-inoperative position, a tripping member axially movable within the die body and engageable with the work for swinging said trigger levers after a predetermined length of thread has been cut, whereby said sleeve member is moved to chaser-inoperative position to permit the release of the work.

8. In a self-opening die for pipe-threading machines, the combination of a die body having longitudin ally extending spring-receiving channels in its periphery, chasers slidably mounted in said die body, a longitudinally shiftable sleeve member splined to said die body and operatively connected to said chasers for controlling their movement in both directions, pins extending radially through said sleeve member and havin flattened ends disposed within said channels, coil springs disposed in said channels and bearing against the flat end portions of said pins for effecting a movement of said sleeve member to chaseroperative position, a spring-loop surrounding said die body and engageable with the ends of said pins for retaining them in said sleeve member, and tripping means retaining said sleeve member in chaser-operative position and controlling the movement of said sleeve member whereby saidchasers are moved to inoperative position to permit the release of the work after cutting thereon a predetermined length of thread. i

9. In a self-opening die for pipe-threading machines, the combination of a cylindrical die body having an annular shoulder thereon adjacent its rear end and longitudinally extending channels open along the periphery of said body, chasers slidably mounted in said die body, a front-plate secured to said die body and forming the forward ends of said channels, a longitudinally shiftable sleeve member splined on said die body against relative rotation by parts extending into some of said channels, said sleeve member having cam connections with the outer ends of said chasers for controlling the movement of said chasers in both directions, projections secured to said sleeve member and extending inwardly into others of said channels, coil springs disposed in said last named channels between said projections and said front-plate for effecting a movement of said sleeve member to a chaser-inoperative position determined by the annular shoulder on said die body, and tripping means retaining said sleeve member in chaser-operative position and controlling the movement ofsaid sleeve member, whereby said chasers are moved to inoperative position after cutting a predetermined length of thread to permit the release of the work.

10. In a self-opening die for pipe-threading machines, the combination of a die body, chasers slidably mounted therein, a shiftable sleeve member slidably mounted on the die body for controlling the movement of said chasers, spring means acting on said sleeve member for effecting movement of said member to chaser-inoperative position, tripping means for controlling movement of said sleeve member including a twopart tubular member slidably mounted within the die body and adjustable in length by a threaded connection, the front part of said tubular member being adapted to engage the end of a pipe, a spring-urged blade-holder slidably mounted within said tubular mem ber, and a cutting blade secured to said blade holder for reaming the end of the pipe by its yieldable engagement therewith, said tubular member and die body having slots for receiving the cutting blade to prevent the relative rotation of the said several parts, and the movement of said tubular member by the work controlling the movement of said sleeve memberto chaser-inoperative position to permovement'therein, a front plate detachably secured to said die body and enclosing the forward ends of said channels, coil springs disposed in said channels and acting between said front plate and said projections for effecting the rearward movement of said sleeve member to chaser-inoperative position, and means retaining said sleeve member in chaser-operative position and controlling the movement of said sleeve member to chaserinoperative position.

12. In a self-opening diefor pipe threading machines, the combination of a diebody having a central recess including peripheral longitudinally-extending grooves, chasers movably mounted in .said die body and retained in normally operative position, and I spring-pressed cutting blades slidably mounted at their edges in said grooves against relative rotation with respect to said die body and adapted for reamingthe end of a pipe received in the die body.

In testimony whereof, I afiix my signature.

FRANK DAVIS. 

